How to Build a Wood Shed

How to Build A Wood Shed

Written by Frank McGill.

In this article, I would like to explain some of the basics of building a wood shed or barn in your backyard. The recession has hit us all pretty hard. We are all trying to find ways to save money while meeting our needs. Well, as your family grows, the need for space grows, and building your own wood shed to store some of your outdoor equipment, your lawn tractor and so forth, may be for you.

The Basics

If you are like most people, you've never built a shed before, so where do you start? What do you do first? You don't have the money to hire a professional, or buy a pre-manufactured shed, but you really need the storage space. Professional plans are quite expensive, and they may be worth the money, but who has the cash to pay someone to design a shed for them?

You will be tempted by free shed plans, but remember, you get what you pay for. You don't know what you are getting or from who. Those free shed plans you see online are not nearly as effective and instructive as those prepared by professionals.

We feel our plans are the best in the business, but let's assume you have already received your download of our plans and you are perusing through them, what do you do first? Well, the first thing you do is to pick a design. We have sheds with Gable Roofs, Gambrel Roofs, and the popular Saltbox Roof Style. Gable Sheds are the easiest to build. Gambrel Roofs often provide additional loft storage space due to the nature of their design. Saltbox style are the most architecturally pleasing designs.

The next thing you do is pick a size that you want to build. This depends on your budget, your storage needs, and the available backyard space you have. Honestly, my personal opinion, is too large is just right enough. You want to build the biggest shed you can afford, given your space constraints. Because it is so much cheaper to build a shed a little bigger then you need now, versus needing a 2nd shed in a few years.

Once you have that figured out, the next thing you need to do is examine our provided bills of material for each shed, and take a trip to your local lumber supply store or Home Depot. It may take several trips depending on your vehicle or trailer and the shed you need to build. Many places deliver. In our opinion, it is best to purchase 1/2 to 3/4 of the material you need first, begin building, and get the rest of the material later when you get halfway done. This will allow you to gauge how much scrap you are using, and trust me, there will always be a need to go back to the hardware store, so just figure that in.

Once you get back to your house, the last thing you need to do before you begin is to pick a site in your backyard, call a buddy, and start building your shed. You start with putting your foundation down, and building it up from there. A typical shed will take from 1 to 3 weekends to put up depending on your experience level. It is generally pretty easy and one of the best ways to increase the value of your home.

The Dirty Details

Whether you're building a stick framed shed, garage, or barn, the construction methods are pretty much the same. What will be different is the material you use for the larger buildings, you'll be using stouter, longer lumber--and more of it! Frame members need to be beefier to span longer distances and to accept insulation. A Wide structure may require 2x10s instead of 2x8s to span the walls without sagging. A garage built in the Midwest that also serves as a workshop will use 2x6s for the wall framing instead of 2x4s to hold the thicker fiberglass insulation needed in cold winters.

The type of foundation you install will also depend on the size of the structure. Most sheds can be built on skids, precast piers, or poured footings. These foundations can be tackled by the average homeowner, but the slab foundation we discuss in our article on slab foundations is best installed by building professionals, as it requires deep footings, reinforced rod to prevent cracks, and a load or two from a cement mixer.

The first step in building a shed, or any structure, is to have the building plans approved by your local building inspector. Ask what they need to inspect and when they need to do it. When you have everything approved, you can begin to prepare your building site and start gathering your materials.

Step 1 - Lay Out the Foundation

If there is one part of building a shed, garage, or barn that's worth some extra time, its laying out and creating the foundation. Small errors can telegraph into the finished structure, causing even larger problems later. Begin laying out your foundation, using batter boards and stakes (batter boards are pointed 2x4s driven into the ground and spanned with 1x4s). Consult your shed plans, and roughly locate the footings with a stake. Then position pairs of batter boards at right angles to each other about 18 inches behind each stake. Stretch a mason's line between adjacent corners, and wrap the line around nails driven into batter boards. Adjust the nails on the batter boards to align the mason's line with the stakes locating the footings. Use a 3-4-5 triangle to make sure the lines are perpendicular.

Step 2 - Dig the Footings

Temporarily loosen the mason's lines so they don't interfere as you dig the footing. In most areas, you will need to dig at least 12 inches below the frost line, check with your local building inspector for footing dimensions. If you're installing a slab, excavate at least 4 inches of soil beneath the slab and add 4 inches of pea gravel for drainage. Then dig a 12 to 16 inch deep trench around the perimeter for a 12 inch wide footing at the bottom.

Step 3 - Build Forms

Slab foundations use forms to define the sides of the slab. These are 2-by boards held in place by stakes. If you're having a slab installed by a contractor, they'll build the forms for you. Before you pour concrete for a slab foundation, add rebar and wire mesh to help prevent cracking. Set #5 rebar on bricks placed in the bottom of the trench. This raises the rebar so that the concrete can flow around it. Lay a 6-mil vapor barrier over the slab section and then place a #10 reinforcing mesh over the slab, keeping it 2 inches from the forms. Insert bricks under the mesh to raise it as you did for the rebar.

Step 4 - Pour Concrete

Now you're ready to pour. If you're pouring your own footings for your shed, be prepared to work your butt off. On a slab foundation, the concrete truck will arrive with a load of concrete and, with the help of a contractor crew, these folks will quickly pour it into the form.

Step 5 - Screed it level

Once concrete has been poured, it's leveled or "striked" with the aid of a screed--typically a long, straight 2x4 or 2x6. The screed spans the form from side to side. As it's dragged across the top, it levels the concrete. After striking, smooth the concrete with a bull float by dragging it carefully over the concrete. Once the finishing is complete, the mist the slab with water and cover it with a layer of plastic. Keep the surface moist for 2 or 3 days.

Step 6 - Install Anchors

With a poured footing or slab foundation, the shed attaches to the footings or slab via anchors set into the concrete. For maximum holding power, these are typically shaped like a J. To install the anchors on poured footings, reposition the mason's lines on the batter boards and use a plumb bob to mark the anchor location in the footing. Push an anchor into the wet concrete and wiggle it to get the concrete to fill around it. Adjust its position so its directly centered under the plumb bob and is plumb. On a slab, snap a chalk line the desired distance in from the edge and then measure and mark anchor locations per your shed plans.

Step 7 - Lay Out Top and Bottom Plates.

Once the foundation is complete, you can start framing the walls, one of the most satisfying parts of build a shed. The best way to make sure that wall studs align is to lay out the top and bottom plates at the same time; these form the top and bottom of the walls. (Note: On slab foundations, the bottom plate is called a mudsill and is usually pressure treated wood.) Start by measuring and cutting plates for one wall at a time--make sure you choose lumber as straight as possible for these critical parts. Align the plate ends and screw them together temporarily. Set the plates on the edge and, measuring from one end, make a mark at 1 1/2 inches and then at 15 1/2 inches (for 16 inch on-center spacing) or 23 1/4 inches (for 24 inch on center spacing). Use a combination square and a pencil to continue these marks across both plates. Then measure and mark a line every 16 or 24 inches from these lines, continuing the full length of the plates. Make an X on the appropriate side of each line to indicate stud placement.

Step 8 - Build Walls

Remove the screws and separate the top and bottom plate. (On a slab foundation, first position the mudsill on the slab and transfer the anchors' locations onto the mudsill; drill appropriate sized holes for the anchors to pass through.) Then cut efficient sufficient studs to length for the wall, and end-nail them to the top and bottom plates, taking care to position the studs over the X's you made on the plates. Cut a scrap of 1x4 to reach from corner to corner of the completed wall, to serve as a brace and to keep the wall square. Attach it to one corner and measure diagonals. Adjust the wall until the diagonal measurements are equal, and then secure the other end of the 1x4 brace.

Step 9 - Frame Rough Openings

If the wall section that you're building includes windows or doors, you'll need to frame rough openings. Cut king, jack, and cripple studs per your shed plans along with a header for each opening. Attach the king studs between the top and bottom plate and secure the jack studs to these. Place the header on top of the jack studs and toenail it to the jack and king studs. Complete the rough opening by installing a sill and cripple studs as needed.

Step 10 - Raise the Wall Section

Before you raise a wall, temporarily attach a pair of scrap wood braces to the rim joists adjacent to the wall you're raising. Then, with the aid of a helper or two, lift the wall section up and set it into place so the bottom plate is flush along the entire front edge of the flooring and so the end of the wall aligns with the end of the floor. (On a slab foundation, make sure all of the anchors pass through the mudsill.)

Step 11 - Level and Brace Wall

Use a level to adjust the wall section as needed to bring it into plumb. When everything looks good, have a helper secure the other end of the scrap wood braces to the wall section with nails or screws. After you've done this, take the time to double check for plumb before moving on to the next wall. Quite often the act of securing the wall to the brace will shift it out of plumb; so readjust it if necessary.

Step 12 - Secure Wall Section to Floor

Attach the wall section to the floor by driving nails or screws every 16 inches or so through the bottom plate and into the floor. About half of the fasteners should penetrate into rim joists, and the other half go into the floor joists. (for a slab foundation, add washers and thread on nuts - don't tighten until all the walls are in placed and leveled). Frame the next wall and continue until all walls are raised. Don't drive nails through the bottom plate in a doorway -- this piece will be cut away when the framing of your shed is complete.

Step 13 - Secure Corners

When all the walls for your shed are in place, you'll need to add extra studs at the corners so that you can securely attach the wall sections to each other. Space these studs away from the end stud with filler blocks. Then start at one corner and nail together the end studs with 16d nails. Repeat at the next corner of the shed. Its a good idea here to check for level and plumb one more time, as the walls may have shifted slightly. Remove the temporary scrap wood braces.

Step 14 - Install the Double Top Plate

The tops of the walls are fixed together by adding another top plate. This double top plate creates a rigid structure that will help support the roof of your shed. Cut the double top plates to length so that they overlap the top plate joints. Secure the double top plate to the top plate with 10d nails every 16 inches or so. Also, drive in 2 nails at the ends of the plates that overlap intersecting walls. Use a hand saw or reciprocating saw to remove the bottom plate in any door openings.

Depending on your shed plans, you may or may not need to add ceiling joists to span the alls. If you do, cut them to length and install them at this time in construction. Small shed plans may not call for ceiling joists at all, or they may use collar ties. Most roof framing is based on the gable roof, where rafters are spaced at 16 or 24 inch increments and secured to the double top plate at their bottom and to the ridge board at the top.

Step 15 - Make a Rafter Template

The most precise and efficient way to cut rafters for your shed is to make a rafter template from a piece of rafter stick (typically 2x4s or 2x6s for sheds). Consult your shed plans and carefully lay out the top and bottom plumb cuts along hte bird's mouth - a notch that's cut so the angle rafter can rest on the double top plate. After you've made the template, cut two rafters and test the fit by holding them temporarily in position with a scrap of 2-by material in between to serve as a ridge board. If everything looks good, cut the remaining rafters you need for your shed.

Step 16 - Lay Out the Rafters

Starting at one end of the shed, measure and mark the position of the rafters on the double top plates, making sure to start at the same end on both sides that you used to layout the wall studs; this ensures that the rafters will be installed directly over the studs. Mark an X on the appropriate side of each line. Trim the ridge board to length and transfer the rafter layout from the double top plates to the ridge board.

Step 17 - Install Rafters

End-nail the first rafter to the ridge board and toenail the second rafter to this. Lift this assembly into place so the bird's mouth notches fit over the double top plates. Have a helper support the opposite end of the ridge board, check to make sure the ridge board is level, and add a brace to keep it in place. Align the bottom of the rafters with the marks on the double top plate. Attach them with 16d nails. Add the end rafters at the opposite end. Then continue adding rafters until the shed roof framing is complete.

Step 18 - Add Fascia

Once the rafters are in place, you can then add the fascia to your shed. Fascia covers the end of the rafters to protect them and provide a more finished look; a common fascia material is 1x4 or 1x6 primed pine. Depending on your shed plans, you may want to cover the end rafters with fascia as well. If so, cut these to length now and attach them with 8d galvanized finish nails. You can butt of the fascia together at the corners or miter cut them. Secure the fascia wit two 8d galvanized nails.

Step 19 - Attach Sheathing

Once the shed roof framing is in place, you can add the roof sheathing. The thickness and type of sheathing you use will depend on local codes. Even if the code allows for thin sheathing, try to avoid anything less than 1/2 thick, as this doesn't provide as solid a nailing base as thicker sheathing offers. In preparation for the asphalt shingles apply 15 pound roofing felt. This type of roofing is easy to apply, very cheap, and will last for years. Exterior grade 5/8 inch thick tongue and groove sheathing is an excellent choice for most shed roofs. Start at the bottom and work your way to the top, making sure the end of each panel falls over the center of a rafter; trim it if necessary. Also, make sure that you stagger the panels so that the joints don't align. This will make your shed roof stronger. Leave a 1/8 inch expansion gap between the panels, and secure them to the rafters with 8d roofing nails every 6 inches or so. Add panels until the entire roof is sheathed.

Step 20 - Attach Roofing Felt to your Shed

Adding a layer of roofing felt on the top of the sheathing and fascia protects the roofing from moisture. To align the rows of roofing felt, measure 33 5/8 inches above the eaves and snap a chalk line. Then allowing for a 2 inch overlap between the strips, snap each succeeding line at 34 inches. Start applying the strips from the bottom up, taking care to align them with the chalk lines. Where two strips meet at a vertical line, over lap them at elast 4 inches. Use only enough staples or nails to hold the felt in place until the shingles are installed on your shed.

Step 21 - Add a Drip Edge

Before adding the asphalt shingles, protect the edges of the roof with a drip edge. A drip edge is malleable aluminum that's performed into a right angle with a slight lip along one edge to help direct water runoff away from the fascia and exterior siding of the shed. Cut a 45 degree miter at each end with metal snips. Press the drip edge in place so it butts firmly up against the fascia, and secure it every 12 inches or so with roofing nails.

Step 22 - Install Shingles

Asphalt shingles use a self-sealing mastic to fasten the shingles together once they're heated by the sun. In order for the first course of shingles to fasten to the front edge of the roof, a special starter row is installed. The starter row is 7 inch strips cut from full shingles and installed upside down along the eaves to position the mastic near the edge, where it will stick to the first full row installed. Secure the starter row with roofing nails 3 inches above the eaves. Install the first course of shingles, allowing 1/2 inch overhang. Snap a chalk line 10 inches up from the bottom of the first course, offsetting horizontally by a half tab. Continue snapping reference lines and adding courses until you reach the ridge.

Step 23 - Attach the Ridge Cap

Use ready made ridge shingles or cut your own 12 inch squares from standard shingles. On the most visible side of the shed, snap a line parallel to and 6 inches down from the ridge. Starting at the end opposite the prevailing wind, apply the singles, leaving a 5 inch exposure; align the edges with the chalk makes. Nail on each side, 5 1/2 inches from the butt and 1 inch from the outside edge.

Step 24 - Install Exterior Siding

Plywood siding is the least expensive and easiest to install siding for a shed. T1-11 exterior tongue-and-groove siding is a good choice for any shed. Start by positioning the first sheet vertically at one corner so its edge is lush with the corner framing. Check that the opposite edge reaches the center of the wall stud; shift the panel and trim as necessary. Attach the siding to the wall studs using 8d galvanized finish nails every 6 inches around the perimeter and every 12 inches elsewhere. Install the remaining sheets, leaving a 1/8 inch expansion gap between the sheets. When possible, apply siding over window and door openings, then cut out the siding with a saber or reciprocating saw.

Step 25 - Add Windows and Doors

Position the prehung window or door in the rough opening and insert pairs of shims around the perimeter. Adjust the shims as necessary to make the unit plumb and level. To secure the window or door, drive galvanized casing nails through the jamb and shims and into the jack studs, sill, and header. Trim off any protruding shims. Secure windows with nailing flanges or pre-installed brick molding to the exterior siding, using galvanized nails driven through the siding and into the framing of the shed.

Step 26 - Finish off with Trim

All that's left to complete your shed is to install trim around the windows and doors, and along the top and/or bottom of the exterior walls, if desired.